A fiber optic component such as a fiber optic network cable or a fiber optic transceiver typically includes a fiber optic connector which is designed to connect with a fiber optic connector of another component in order to form a cohesive communications medium for carrying light signals. One type of fiber optic connector includes a ferrule (e.g., a precision-molded ceramic, metal, silicon, or plastic part) which terminates a set of fiber ends (e.g., one end, four ends, eight ends, 12 ends, etc.). The manner in which the ferrule terminates the set of fiber ends typically defines one of several standard fiber optic interface formations (e.g., an MT ferrule which terminates a 1xc3x974 array of fiber ends, a 2xc3x974 array, a 1xc3x9712 array, etc.).
Fiber optic connectors typically include alignment structures (e.g., guide pins, alignment sleeves, etc.) that insert into, or engage around, other alignment structures to align fiber optic interfaces, which are defined by the fiber ends and the ferrules of the connectors, and thus form a set of fiber optic connections. Such fiber optic connections are separable fiber optic junctions that allow light energy to pass therethrough.
Fiber optic component manufacturers attempt to improve the reliability of their fiber optic connectors such that fiber optic signals passing through the fiber optic connections tend to be relatively error-free, and well-suited for traveling long distances. In particular, such manufacturers typically contour and clean (e.g., polish) the fiber optic interfaces so that their formed connections provide maximum light energy transfer and minimal light signal distortion.
Some fiber optic component manufacturers provide fiber optic connectors with doors to cover the fiber optic interfaces in order to maximize the ferrule cleanliness, provide eye protection and to further protect it from damage. One conventional fiber optic connector includes a fixed number of ferrule assemblies (e.g., four), and a housing, which defines an internal cavity for holding the ferrule assemblies. The connector further includes (i) a first set of doors which is hinged to the housing and which covers a first opening into the internal cavity, and (ii) a second set of doors which is also hinged to the housing and which covers a second opening on the other side of the internal cavity.
To fully assemble the connector, a technician inserts the terminated ferrule assemblies into the internal cavity defined by the housing through the first set of doors until the ferrule assemblies lock in place within the housing. That is, the ferrule assembly end-faces push the first set of doors open, and then slide into fixed positions within the housing. At this point, the fiber optic interfaces of the ferrule assemblies face the second set of doors, which are closed in the unmated condition to protect against contamination by the environment in which they are operating. Contaminants such as dirt, dust, oil, condensation, etc. are typical forms of interference which could collect within an exposed cavity and degrade optical performance. Additionally, if there are any light signals which are currently active in the system and exiting the fiber optic interfaces, such signals will hit the second set of doors rather than escape the connector and perhaps injure a bystander or technician who is looking directly into the system (e.g., eye damage caused by laser contact with the retina.)
To mate this first connector with another fiber optic connector, the technician moves the ferrule assemblies of the other connector toward the second set of doors of the first connector until the ferrule assemblies of the other connector (i) push the second set of doors open and (ii) are inserted into the internal cavity defined by the housing of the first connector. The technician continues moving the ferrule assemblies of the other connector toward the first connector until the ferrule assemblies of both connectors align (e.g., using alignment pins) and abut. A locking mechanism typically holds the ferrule assemblies together thus maintaining the formed set of fiber optic connections. A fiber optic connector which is similar to that described above is Molex Part No. 86105 which is provided by Molex Inc. of Lisle, Ill.
Unfortunately, there are deficiencies to the above-described conventional fiber optic connectors, which require the ferrule assemblies of a corresponding connector to push the connector doors open. In such a configuration, it is quite common for ferrule assemblies to become contaminated or sustain damage. It is critical that the end-faces of a fiber optic ferrule remain clean and free of any and all imperfections. By using the ferrule end-face or a corresponding alignment pin to open the door, simply increases the risk and likelihood of both of the above stated concerns.
In addition, alignment pins extending from the ferrule end-faces can bend resulting in misalignment, scratching, scraping, and/or an inability to mate. Furthermore, if the doors being contacted by the ferrules were to inadvertently bind or lock up, the doors could again cause pin or end-face damage.
Moreover, once a fiber optic interface is damaged, cost and time associated with replacing the interface can be significant.
Furthermore, the housing of the above-described conventional fiber optic connector is relatively inflexible and does not lend itself to easy scaling. That is, if the manufacturer desired a fiber optic connector with a different number of ferrule assemblies (e.g., a housing which holds six ferrule assemblies rather than four), the manufacturer is required to re-engineer the housing design to accommodate a different number of doors or differently sized doors, and almost certainly retool all the equipment associated for the new housing.
In contrast to the above-described conventional fiber optic connector which uses ferrule assemblies to push doors open, the invention is directed to fiber optic connecting techniques which use a module that houses one or more fiber optic interfaces, i.e., a set of fiber optic interfaces. (In general, the use of the term xe2x80x9csetxe2x80x9d within this document is intended to mean xe2x80x9cone or morexe2x80x9d.) The module includes a shroud, which protects the set of fiber optic interfaces when in one location, and exposes the set of fiber optic interfaces when in another location. The shroud can operate in conjunction with a set of doors, which actuate in response to shroud movement. Such operation alleviates the need for door actuation in response to contact with ferrule assemblies as required by conventional fiber optic connectors thus avoiding the risk of ferrule assembly damage and contact contamination.
Furthermore, the module can be readily combined with other fiber optic connector assemblies within similar modules in a variety of configurations with no additional retooling costs, (e.g., a manufacturer can manufacture a first assembly having four modules, and a second assembly having six modules) by simply using different sized module carriers (e.g., a module housing or frame which is configured to carry the modules) fabricated using insert based tooling.
One embodiment of the invention is directed to a module for housing fiber optic interfaces. The module includes a fiber optic interface holder, which is configured to hold the optics, and a shroud coupled to the optical holder. The shroud is configured to move relative to the optical holder along an axis defined by the optical holder such that, when the optical holder holds the fiber optic interfaces, the shroud (i) protects the fiber optic interfaces when the shroud is in a first location along the axis defined by the optical holder, and (ii) exposes the fiber optic interfaces when the shroud is in a second location along the axis defined by the optical holder. In one arrangement, the shroud operates with a set of doors, which actuate in response to movement of the shroud along the axis. Such operation alleviates the need for door actuation in response to contact with ferrule assemblies in conventional fiber optic connectors thus avoiding the risk of ferrule assembly damage or contamination, while still providing the needed eye protection.
Another embodiment of the invention is directed to a method for making a fiber optic connector assembly. The method includes the steps of receiving a set of fiber optic modules similar to that described above, fitting a set of fiber optic interfaces into the set of fiber optic modules, and installing a set of latch modules and the set of fiber optic modules having the fitted set of fiber optic interfaces into a module carrier. This method enables a manufacturer to make a variety of fiber optic connector assemblies simply by varying the size of the module carrier (e.g. assembling specific long or short modularized xe2x80x9cbuilding blocksxe2x80x9d necessary to meet the customers requirements) and by choosing a suitable combination of fiber optic and latch modules to be carried by the modularized carrier.
With this modularized method, each connector is essentially independent and self-contained thus enabling the manufacturer to simply change the size of the housing without concern for accommodating additional or fewer protective door and cavities.
Yet another embodiment of the invention is directed to a method for connecting to a fiber optic module having a module base which holds a set of fiber optic interfaces. The method includes the steps of (a) placing a connecting module against an end of the fiber optic module to cover the end of the fiber optic module, and (b) moving a shroud of the fiber optic module along an axis, which is defined by a fiber optic interface holder coupled to the shroud, from a first location to a second location. Accordingly, the shroud protects the set of fiber optic interfaces when the shroud is in the first location along the axis. Additionally, the shroud exposes the set of fiber optic interfaces when the shroud is in the second location along the axis. The method further includes the step of (c) precisely aligning a set of fiber optic interfaces of the connecting module with the set of fiber optic interfaces to form a set of fiber optic connections.